A neuropathological study of novel RTTN gene mutations causing a familial microcephaly with simplified gyral pattern

Abstract

Background: The RTTN gene encodes Rotatin, a large centrosomal protein involved in ciliary functions. RTTN mutations have been reported in seven families and are associated with two phenotypes: polymicrogyria associated with seizures and primary microcephaly associated with primordial dwarfism.

Case: A targeted exome sequencing of morbid genes causing cerebral malformations identified novel RTTN compound heterozygous mutations in a family where three pregnancies were terminated because a severe fetal microcephaly was diagnosed. An autopsy performed on the second sib showed moderate growth restriction and a microcephaly with simplified gyral pattern. The histopathological study discovered a malformed cortical plate.

Conclusions: The present study confirms the involvement of RTTN gene mutations in microcephaly with simplified gyral pattern and describes the observed abnormal neuropathological findings.

Keywords: RTTN mutations; Rotatin; fetopathology; microcephaly; neuropathology; prenatal diagnosis.